MAX9075 查看數據表（PDF） - Maxim Integrated

零件编号

产品描述 (功能)

生产厂家

MAX9075

Low-Cost, Ultra-Small, 3µA Single-Supply Comparators

Maxim Integrated 

MAX9075/MAX9077

Low-Cost, Ultra-Small, 3µA

Single-Supply Comparators

PIN

MAX9075

MAX9077

SOT23

SC70 µMAX/SO SOT23

1

1

—

—

—

—

1

1

2

2

4

2

3

3

—

—

—

—

3

4

4

4

—

—

—

—

2

3

5

5

8

8

—

—

5

5

—

—

6

6

—

—

7

7

NAME

OUT

OUTA

GND

IN+

INA+

IN-

INA-

VCC

INB+

INB-

OUTB

Pin Description

FUNCTION

Comparator Output

Output of Comparator A

Ground

Noninverting Comparator Input

Noninverting Input of Comparator A

Inverting Comparator Input

Inverting Input of Comparator A

Positive Supply Voltage

Noninverting Input of Comparator B

Inverting Input of Comparator B

Output of Comparator B

Detailed Description

The MAX9075/MAX9077 feature a 580ns propagation

delay from an ultra-low supply current of only 3µA per

comparator. These devices are capable of single-sup-

ply operation in the 2.1V to 5.5V range. Large internal

output drivers allow rail-to-rail output swing with up to

2mA loads. Both comparators offer a push-pull output

that sinks and sources current.

Comparator Output

The MAX9075/MAX9077 are designed to maintain a

low-supply current during repeated transitions by limit-

ing the shoot-through current.

Noise Considerations, Comparator Input

The input common-mode voltage range for these

devices extends from 0V to VCC - 1.2V. Unlike many

other comparators, the MAX9075/MAX9077 can oper-

ate at any differential input voltage within these limits.

Input bias current is typically -5nA if the input voltage is

between the supply rails.

Although the comparators have a very high gain, useful

gain is limited by noise. The comparator has a wide-

band peak-to-peak noise of approximately 70µV.

Applications Information

Adding Hysteresis

Hysteresis extends the comparator’s noise margin by

increasing the upper threshold and decreasing the

lower threshold. A voltage divider from the output of the

comparator sets the trip voltage. Therefore, the trip

voltage is related to the output voltage. Set the hystere-

sis with three resistors using positive feedback, as

shown in Figure 1.

The design procedure is as follows:

1) Choose R3. The leakage current of IN+ may cause a

small error; however, the current through R3 can be

approximately 500nA and still maintain accuracy.

The added supply current due to the circuit at the

trip point is VCC/R3; 10MΩ is a good practical value

for R3, as this keeps the current well below the sup-

ply current of the chip.

2) Choose the hysteresis voltage (VHYS), which is the

voltage between the upper and lower thresholds. In

this example, choose VHYS = 50mV and assume

VREF = 1.2V and VCC = 5V.

3) Calculate R1 as follows:

R1 = R3 x VHYS/VCC = 10MΩ x 0.05/5 = 100kΩ

6

Maxim Integrated

Share Link: